DAYS 1-5 (MAY 25-29)

Popcorn showers dominated the Saturday third of Memorial Day Weekend. Now it’s time for the Sunday middle third, and while today won’t be a top 10 day, it’ll be nicer than yesterday, in that the shower threat is much lower. While some areas have abundant sun to start the day, others are under cloud patches, and the general trend will be for a lot of diurnal clouds to pop up in any sunnier areas, due to colder air lingering aloft with upper level low pressure centered to our northeast, but us still in the cold pool. A few of these clouds can grow to produce passing showers, but the coverage will be far less than yesterday. Monday (Memorial Day) will be even better weather-wise, as the upper low loses influence and high pressure builds in from the west. While we still will have some clouds popping up, they will be “fair-weather” clouds as I don’t expect them to produce any showers. Coastal areas will end up cooler Monday due to a light sea breeze there. High pressure will remain dominant Tuesday with fair, pleasant weather. At midweek, we see another transition to somewhat unsettled weather, but this time it doesn’t look anything like what we just went through. A weaker area of low pressure will approach from the southwest Wednesday with increasing clouds and a southeasterly air flow keeping the coast coolest. Thursday we find ourselves in a southerly air flow with more humidity, variable cloud cover, and a chance of showers, between high pressure over the Atlantic and low pressure to our west.

TODAY: Sun/cloud mix. A passing shower possible. Highs 61-68. Wind NW 5-15 MPH.

TONIGHT: Lots of clouds early / decreasing clouds after. Lows 47-54. Wind N under 10 MPH.

MONDAY (MEMORIAL DAY): Sun/cloud mix. Highs 66-73. Wind N up to 10 MPH but some coastal sea breezes developing.

MONDAY NIGHT: Partly cloudy. Lows 47-54. Wind N up to 10 MPH.

TUESDAY: Mostly sunny. Highs 66-73, coolest coast. Wind N to E up to 10 MPH.

TUESDAY NIGHT: Mostly clear. Lows 49-56. Wind E to SE under 10 MPH.

WEDNESDAY: Increasing clouds. Highs 60-67, coolest coast. Wind SE 5-15 MPH.

WEDNESDAY NIGHT: Mostly cloudy. Lows 52-59. Wind SE to S up to 10 MPH.

THURSDAY: Variably cloudy. Chance of showers. Highs 66-73, coolest South Coast. Wind S 5-15 MPH.

DAYS 6-10 (MAY 30 – JUNE 3)

A low pressure trough aloft and a series of surface troughs bring a chance of showers (possibly thunderstorms) during the last couple days of May. Upper level low pressure hangs around then slowly moves away the first few days of June with a drying trend but temperatures near to below normal.

DAYS 11-15 (JUNE 4-8)

Guidance waffles between weak blocking and progressive pattern prognostications, so there is little change in the low confidence outlook which leans slightly cool but not excessively wet.

DAYS 1-5 (MAY 24-28)

The weather this Memorial Day Weekend will most certainly trend nicer compared to recent days, especially the soaking rainstorm with moderate to strong coastal winds we just experienced. That storm system weakened as it wandered away from us yesterday, “away” being a loosely-used term here, because we are still feeling its effects and will continue to do so for all 3 days of the weekend, but not to the degree we did during the last few days. Improvement comes as a drying trend takes place around the back side of the low and its upper level counterpart. But there is enough moisture in place today for a lot of clouds and a few rounds of showers in the region. In fact, I apologize for the delay to later-than-usual posting, as one such shower area moving into the area was taking place as a clearing slot in the sky allowed the sun to shine through, creating a somewhat-rare morning rainbow in the western sky at my location, which was in place for nearly 75 minutes and had me lining up some photographs at various city landmarks here in Woburn. This is an area of showers coming back in from the west around the back side of low pressure, which elongates in trough form westward. That trough will be moving through the region today, and while the majority of the hours are rain-free at any given location, additional pop up showers can occur from midday through mid afternoon in a trend from west to east, after which some additional sunny breaks may arrive for late day. Maybe a few more rainbows will be visible in some locations, but this time it would be to the east southeast as the sun prepares to set on the opposite side of the sky. Keep a look-out should you get tagged by a late-day shower followed by sun. I don’t think I’ve ever had a morning rainbow and a late-day rainbow on the same day, at least while I’ve been observing. Maybe today will be the day. Anyway, back to the actual weather forecast… Sunday’s weather improves, but we’ll still see clouds coming around the back side of the low and additional pop-up clouds that can release a shower, but the odds of seeing one of those are much lower than today. While we’ll have the pop-up clouds again Monday, I think these ones will fail to produce showers, and Memorial Day will turn out the nicest of the three day weekend. This will be favorable for the many outdoor observances and ceremonies scheduled for the day. High pressure then builds in for a nice day Tuesday. I’m watching low pressure to the southwest of us by Wednesday which may spread a blanket of clouds back into the region, aided by a possible onshore flow by that time. Not quite sure how that evolves yet, so “day 5” is a fairly uncertain forecast at this point and I’ll refine it going forward from here.

TODAY: Lots of clouds. Light showers mainly west and north of Boston this morning. Scattered showers redevelop west to east midday to mid afternoon. Highs 57-64. Wind W 5-15 MPH.

TONIGHT: Variably cloudy. Lows 45-52. Wind NW 5-15 MPH.

SUNDAY: Partly sunny. Slight chance of a passing shower. Highs 61-68. Wind NW 5-15 MPH.

SUNDAY NIGHT: Partly cloudy. Lows 48-55. Wind NW up to 10 MPH.

MONDAY (MEMORIAL DAY): Sun/cloud mix. Highs 66-73. Wind NW up to 10 MPH but some coastal sea breezes developing.

MONDAY NIGHT: Partly cloudy. Lows 47-54. Wind N up to 10 MPH.

TUESDAY: Mostly sunny. Highs 66-73, coolest coast. Wind N to E up to 10 MPH.

TUESDAY NIGHT: Partly cloudy. Lows 49-56. Wind E to SE under 10 MPH.

WEDNESDAY: Mostly cloudy. Highs 60-67, coolest coast. Wind SE 5-15 MPH.

DAYS 6-10 (MAY 29 – JUNE 2)

Again this period is a lower then average forecast confidence time frame. Still leaning toward a southerly to variable flow in the May 29-31 time frame with a frontal system and disturbance bringing some shower chances, then a fair weather trend to start June. Temperatures not far from normal – no extremes.

DAYS 11-15 (JUNE 3-7)

A hint of a weaker block (high pressure to north / low pressure to south) leaves this longer range forecast period very uncertain at this point. Leaning toward the cooler side of average with enough high pressure for mostly dry weather, but with continued low confidence, so check updates.

DAYS 1-5 (MAY 23-27)

An impressive late May storm system delivered a healthy rainfall to the region yesterday into early today including some potent thunderstorms for portions of southeastern MA. While wind gusts were strong at times, the rainfall amounts of 2 to 5 inches (even a few higher amounts) were the more notable aspect of the system, and while some minor flooding occurred, this rainfall should be what finishes off any moderate drought that still existed in our region, putting us in a much better place heading toward summer regarding that. But that’s something to monitor longer-term. In the shorter-term, the low pressure area that brought us these conditions will still have an impact on the region going into the long weekend. We’ll be under the influence of its circulation, even though it weakens and lifts into Maine and eventually Atlantic Canada. Because we are talking about a “vertically stacked” (mature surface low pressure aligned with its upper level counterpart), and no powerful jet stream moving it along, the entire process of ridding ourselves of it is slow. However, with time, it aids in improving the weather, helping to draw drier air into our region. At first though, this will be less apparent with some drizzle and a few showers around today, and a tongue of moisture even increasing the rainfall coverage for several hours this evening / tonight. Saturday we’ll keep a lot of cloud cover around, but the shower coverage will be less again. Although some of the scattered ones that do occur can be a little heavier than what’s around today, favoring midday to mid afternoon. Behind these we see an attempt at some clearing and may see some sun before the day’s over Saturday, but additional cloudiness still associated with the storm’s circulation will not allow for complete clearing, even Sunday, which will be a nicer day overall. Chilly air still lingering aloft means that I can’t rule out pop up isolated showers Sunday, but I would not alter any outdoor plans because of that forecast other than being aware of the slight chance. Memorial Day itself, Monday, will feature fair weather as high pressure builds into the Great Lakes. I’ve been skeptical of this being the start of a fair weather stretch, but the trend on reliable guidance has been to build that high into New England and keep fair weather going on Tuesday next week, so I’ll lean into this trend for now.

TODAY: Mostly cloudy. Patchy drizzle. Chance of passing showers. Highs 52-59. Wind N 5-15 MPH, higher gusts.

TONIGHT: Cloudy. Showers likely. Wind W 5-15 MPH, higher gusts.

SATURDAY: Mostly cloudy through mid afternoon with isolated to scattered showers. Partly sunny late-day. Highs 55-62. Wind W 5-15 MPH, higher gusts.

SATURDAY NIGHT: Variably cloudy. Lows 45-52. Wind NW 5-15 MPH.

SUNDAY: Partly sunny. Slight chance of a passing shower. Highs 61-68. Wind NW 5-15 MPH.

SUNDAY NIGHT: Partly cloudy. Lows 48-55. Wind NW up to 10 MPH.

MONDAY (MEMORIAL DAY): Sun/cloud mix. Highs 66-73. Wind NW up to 10 MPH.

MONDAY NIGHT: Partly cloudy. Lows 47-54. Wind N up to 10 MPH.

TUESDAY: Mostly sunny. Highs 66-73, coolest coast. Wind N to E up to 10 MPH.

DAYS 6-10 (MAY 28 – JUNE 1)

This is not a high confidence forecast at this time. Leaning toward high pressure dominating with fair weather May 28 and a little increase in moisture with a pop up shower chance from a more southerly flow May 29. Somewhat unsettled with a low pressure trough and frontal system traversing the region May 30-31, but does not like a big storm system. June would begin with fair weather if this scenario played out as prognosticated. That’s already more specific than I’d like to be for a 6 to 10 day forecast, so keep track of updates for some changes / adjustments to this outlook.

DAYS 11-15 (JUNE 2-6)

A hint of a weaker block (high pressure to north / low pressure to south) leaves this longer range forecast period very uncertain at this point. Leaning toward the cooler side of average with enough high pressure for mostly dry weather, but with very low confidence.

DAYS 1-5 (MAY 22-26)

A late May coastal storm will impact our region today into Friday, with some lingering effects into the start of the Memorial Day Weekend as well. Today’s weather will feature the maximum effects of the storm system, as a redeveloped low pressure center over the Mid Atlantic cuts across far southeastern New England tonight. Ahead of it rain takes over, along with increasing northeasterly winds, strongest along the coast, and to go along with it unseasonably chilly air making it feel more like late March or early April. The impacts of this system will be noticeably less in the western reaches of the WHW forecast area, and even more so outside of it as you get west of the Connecticut River – more like a benign rain event with a breeze. As the low center lifts northeastward, it will begin to weaken as it heads through the Gulf of Maine into Atlantic Canada. Our wind at that time will back to north, eventually northwest, and wrap-around moisture associated with the storm system will still result in bouts of showers Friday and Saturday, but it appears the bulk of the rainfall may occur Friday night, leaving more rain-free times for both of those days. Upper level low pressure will also be drifting across the region Saturday and exiting as we move through Sunday and Monday. While I cannot rule out a pop-up shower Sunday, I think the day will be generally a rain-free one, and Memorial Day itself should be absent of any rain chances, with favorable conditions for outdoor observances.

TODAY: Overcast. Rain overspreads the region during this morning then continues, possibly heavy at times. Areas of drizzle and fog increasing too. Highs 46-53. Wind NE increasing to 15-30 MPH, higher gusts, especially coast, with frequent gusts 35+ MPH and peak gusts 50+ MPH favoring Cape Cod, but not reaching those levels until evening.

TONIGHT: Overcast. Rain, gradually tapering off overnight. Lows 45-52. Wind NE to N 15-30 MPH, higher gusts especially along the coast.

FRIDAY: Mostly cloudy. Patchy drizzle. Chance of passing showers. Highs 52-59. Wind N 5-15 MPH, higher gusts.

FRIDAY NIGHT: Cloudy. Showers likely. Wind NW 5-15 MPH, higher gusts.

SATURDAY: Mostly cloudy. Scattered to isolated showers. Highs 55-62. Wind W 5-15 MPH, higher gusts.

SATURDAY NIGHT: Variably cloudy. Lows 45-52. Wind NW 5-15 MPH.

SUNDAY: Partly sunny. Slight chance of a passing shower. Highs 61-68. Wind NW 5-15 MPH.

SUNDAY NIGHT: Partly cloudy. Lows 48-55. Wind NW to variable up to 10 MPH.

MONDAY (MEMORIAL DAY): Sun/cloud mix. Highs 66-73, cooler along the coast. Wind variable up to 10 MPH with coastal sea breezes.

DAYS 6-10 (MAY 27-31)

Watching for potential unsettled weather from another low pressure trough heading through next week, but this part of the outlook remains highly uncertain. Temperatures below normal for the final stretch of May.

DAYS 11-15 (JUNE 1-5)

A weakening of blocking and a somewhat more progressive pattern evolves. The outlook here would be a little drier overall, with near to below normal temperatures.

DAYS 1-5 (MAY 21-25)

A quick breather before our next “weathermaker” aka “The May Nor’easter” comes along. Low pressure heads for the Great Lakes today as we have a marine air flow here. There is enough dry air about to break up some of the lower cloud cover so some areas see a few peeks of sunshine this morning. However, a more extensive high to mid level cloud deck will be advancing in from the west and southwest ahead of our developing storm system. The aforementioned low pressure area will redevelop in the Mid Atlantic and head our way, taking a track right across far southeastern New England (Cape Cod / Islands) late Thursday and early Friday. We catch it in its peak intensity cycle too, maximizing the rain, wind, and chilly air with it. This takes place during the day Thursday, into the evening, before diminishing. The low pressure center weakens as it wanders through the Gulf of Maine toward Atlantic Canada, and on its back side, while Friday is still unsettled, it will be less wet, less windy, but still cool. We then reach the Memorial Day Weekend at which time we’ll take one step back on Saturday as the remains of the original low pressure area come across the region as a trough with lots of clouds and a chance of showers, before improvement arrives Sunday in the wake of that system. Tomorrow’s update will expand upon the outlook for the entirety of the Memorial Day Weekend, including the holiday itself which will be “day 5”.

TODAY: Mostly cloudy. Patchy drizzle this afternoon. Highs 52-59, coolest coastal areas. Wind NE 5-15 MPH, gusts 20+ MPH.

TONIGHT: Cloudy. Areas of drizzle and fog. Lows 45-52. Wind NE 10-20 MPH, higher gusts especially along the coast, up to 30+ MPH overnight.

THURSDAY: Overcast. Rain likely and can be heavy at times. Drizzle/fog. Highs 47-54. Wind NE 15-30 MPH, higher gusts, especially coastal areas.

THURSDAY NIGHT: Overcast. Rain, gradually tapering off overnight. Lows 45-52. Wind NE to N 10-20 MPH, higher gusts especially along the coast.

FRIDAY: Mostly cloudy. Patchy drizzle. Chance of passing showers. Highs 52-59. Wind N 5-15 MPH, higher gusts.

FRIDAY NIGHT: Variably cloudy. Chance of a shower. Lows 43-50. Wind N to NW 5-15 MPH.

SATURDAY: Mostly cloudy. Additional showers likely. Highs 54-61. Wind NW 5-15 MPH, higher gusts.

SATURDAY NIGHT: Variably cloudy. Lows 45-52. Wind NW 5-15 MPH.

SUNDAY: Partly sunny. Highs 61-68. Wind NW 5-15 MPH.

DAYS 6-10 (MAY 26-30)

Memorial Day (May 26) looks fair and milder at this point. Watching for potential unsettled weather from another low pressure trough heading through next week, but this part of the outlook is highly uncertain currently. Temperatures trend cooler again.

DAYS 11-15 (MAY 31 – JUNE 4)

Gradual shift from blocking to progressive pattern means briefer unsettled periods and more variable temperatures, but still averaging near to below normal.

DAYS 1-5 (MAY 20-24)

We’re still on the back-side of low pressure here with a cool breeze and lots of clouds, but today will be free of any rain threat. That low wanders away into the North Atlantic and high pressure holds to our north through midweek. A redeveloping omega block will send its eastern low pressure member our way to the south of the high pressure area mid to late week, resulting in another slow moving rain and wind event, along with a chill that’ll make it feel like much earlier in the spring than it is. We’ll start to see improvement, slowly, as we head through Friday and to the start of the weekend, but the pattern is one that doesn’t allow the storm system to exit quickly, so we’ll still feel its effects during this time in the form of below normal temperatures, clouds, and a shower chance despite a drier trend.

TODAY: Lots of clouds / limited sun. Highs 56-63. Wind N 5-15 MPH, gusts 20+ MPH.

TONIGHT: Mostly cloudy. Lows 45-52. Wind NE up to 10 MPH.

WEDNESDAY: Cloudy. Chance of drizzle. Highs 52-59, coolest coastal areas. Wind NE 5-15 MPH, gusts 20-25 MPH coastal areas.

WEDNESDAY NIGHT / THURSDAY: Overcast. Rain likely. Areas of fog. Temperatures fall to 45-52 then steady. Wind NE 10-20 MPH inland, 20-30 MPH coast, higher gusts.

THURSDAY NIGHT: Overcast. Periods of rain / drizzle. Temperatures steady 45-52. Wind NE 10-20 MPH, higher gusts.

FRIDAY: Mostly cloudy. Additional showers / drizzle, tapering off with time. Highs 52-59. Wind N 10-20 MPH, higher gusts.

FRIDAY NIGHT: Variably cloudy. Chance of a shower. Lows 43-50. Wind N 10-20 MPH, higher gusts.

SATURDAY: Lots of clouds / some sun. Chance of a shower. Highs 57-64. Wind N 10-20 MPH, higher gusts.

DAYS 6-10 (MAY 25-29)

Upper level low pressure weakens but hangs around during the May 25-26 Memorial Day Weekend time period with a daily chance of diurnal showers. However much of the time will be rain-free, albeit continued cooler than normal. A brief break May 27? Watching another low pressure area and rain threat potential for later in the period with continued below normal temperatures.

DAYS 11-15 (MAY 30 – JUNE 3)

Wet weather threat early in the period then a drier trend with a gradual shift from a blocking to more progressive pattern. Temperatures near to below normal. Day-to-day details TBD.

DAYS 1-5 (MAY 19-23)

Low pressure areas will be dominating our weather for the next 5 days. Today, we find ourselves on the back side of a large low pressure circulation (both surface and aloft) over southern Atlantic Canada and the adjacent North Atlantic waters. This cool pool will keep us cool and breezy with a sun/cloud mix, clouds eventually dominating, maybe with a passing shower today. The shower threat goes away but some clouds remain on Tuesday as a narrow extension of a larger high pressure area to our north tries to nose into our region. But this miniscule high pressure intrusion will be brief. The evolution of a new omega block will put its eastern low pressure member into our region from mid to late week, and surface low pressure associated with it will head from the Ohio Valley toward the Great Lakes, redeveloping near the Mid Atlantic Coast, taking a track that will bring us a chilly rain later Wednesday through Thursday, tapering off Friday – a spell of weather that will remind you of March or early April rather than late May. But there you have it…

TODAY: Sun/cloud mix with clouds becoming dominant. Chance of a passing rain shower, mainly southern NH / northeastern MA. Highs 59-66. Wind NW 10-20 MPH, gusts as high as 30 MPH.

TONIGHT: Variably cloudy. Lows 45-52. Wind N 5-15 MPH, higher gusts.

TUESDAY: More sun than clouds morning / more clouds than sun afternoon. Highs 57-64. Wind N 5-15 MPH, higher gusts.

TUESDAY NIGHT: Mostly cloudy. Lows 46-53. Wind NE up to 10 MPH.

WEDNESDAY: Cloudy. Rain arriving southwest to northeast by late-day. Highs 53-60, coolest coastal areas. Wind NE to E 5-15 MPH.

WEDNESDAY NIGHT / THURSDAY: Overcast. Rain likely. Areas of fog. Temperatures fall to 45-52 then steady. Wind E to NE 10-20 MPH, higher gusts especially in coastal areas.

THURSDAY NIGHT: Overcast. Periods of rain / drizzle. Temperatures steady 45-52. Wind NE 10-20 MPH.

FRIDAY: Mostly cloudy. Additional showers / drizzle, tapering off with time. Highs 52-59. Wind N 10-20 MPH.

DAYS 6-10 (MAY 24-28)

Upper level low pressure weakens but hangs around during the May 24-26 Memorial Day Weekend time period with a daily chance of diurnal showers. However much of the time will be rain-free, but cooler than normal. Yet another low pressure area brings the chance of rain May 27-28 with continued below normal temperatures.

DAYS 11-15 (MAY 29 – JUNE 2)

A slow transition from blocking to zonal flow is expected to take place. Episodes of passing showers but drier overall. Temperatures near to below normal. Day-to-day details TBD.

DAYS 1-5 (MAY 18-22)

Stacked low pressure (low pressure surface and aloft over the same area) will drift east southeast from Ontario / Maine to southern Atlantic Canada and the adjacent Atlantic Ocean through Monday, wandering away Tuesday as a weak ridge of high pressure builds in. The low pressure area will impact our weather through Monday with cooler, less humid air, lots of clouds, and a few passing showers – although most times will be rain-free in any given location. One detail to note: If you walk outside this morning, especially while there is still enough sun around, it will feel quite mild. This is because a surface occluded front that moved through overnight did not introduce a big change in air mass, only a modest one. The dew point has only dropped slightly, along with the temperature, but during the day today the former will continue to drop while the latter rises very little. This, combined with eventual abundant cumulus and stratocumulus cloud cover, will have the net effect of a cool-down, of course augmented by an increasingly gusty breeze on the back side of low pressure. This will set us up for a continuation of the dominant cloud / interval of sun type of sky on Monday, when a few additional passing showers are possible, along with a cool, gusty breeze. Yesterday, I felt a bit more optimistic about a sunnier Tuesday, but today, not so much. A forecaster can be lead astray by guidance that is showing things moving along too quickly in comparison to what actually happens. Yesterday, I had hopes that high pressure would overtake the region Tuesday enough to keep cloudiness away, but it appears that our region will still be close enough to upper level low pressure and resultant cool air above us that we will still have quite a few stratocumulus clouds about. This time, however, I can confidently keep the shower threat out of the forecast – so expect a dry day Tuesday, despite the lack of full sun. We’ll also see a breeze, though not as gusty as Monday, and cool conditions. So now you think, “ok, we paid our dues with this upper low, right? and it has to warm up and be nice next, right???” … Sorry, not correct. Our next low pressure area in the hybrid progressive / blocking pattern (high pressure eastern Canada, low pressure to the south), arrives at midweek. While there are some guidance differences, the general idea is a slightly elongated low pressure area will move our way via the Ohio Valley and Mid Atlantic, spreading its cloud shield into the region on Wednesday. Rain follows, along with a robust onshore flow and very cool air. This is likely to continue through Thursday, though there are some questions as to how deeply into the rain shield we end up. A little stronger high to the north could suppress the low far enough south for a lighter rainfall event. If this is not the case, a healthier soaking rainfall occurs – a May nor’easter of sorts – certainly not unprecedented but not something we see every year late in the 3rd month of meteorological spring. One definite silver lining, this likely event along with recent events continue to combine to reduce the drought / abnormally dry conditions that have affected the region for quite some time. I’ll continue to fine-tune the midweek forecast the next few days…

TODAY: Cloud / sun mix before clouds becoming dominant. A passing shower is possible any time this afternoon / early evening, favoring I-90 northward. Highs 62-69. Wind W to NW 5-15 MPH, gusts 20-25 MPH.

TONIGHT: Mostly cloudy. Lows 46-53. Wind NW 5-15 MPH and gusty.

MONDAY: Lots of clouds / intervals of sun. A passing shower possible. Highs 61-68. Wind NW 10-20 MPH, gusts as high as 30 MPH.

MONDAY NIGHT: Variably cloudy. Lows 45-52. Wind N 5-15 MPH, gusty.

TUESDAY: Limited sun / lots of clouds. Highs 59-66. Wind N to NE 5-15 MPH.

TUESDAY NIGHT: Considerably cloudy. Lows 46-53. Wind NE up to 10 MPH.

WEDNESDAY: Cloudy. Rain arriving southwest to northeast by late-day. Highs 53-60, coolest coastal areas. Wind NE to E 5-15 MPH.

WEDNESDAY NIGHT / THURSDAY: Overcast. Rain likely. Areas of fog. Temperatures fall to 45-52 then steady. Wind E to NE 10-20 MPH, higher gusts especially in coastal areas.

DAYS 6-10 (MAY 23-27)

Improving weather but still cool with a possible shower on May 23 as low pressure moves away. Gradually weakening upper level low pressure over the region during the Memorial Day Weekend (May 24-26) – this would promote a daily chance of showers and a few thunderstorms but also many dry hours. Another low pressure area may bring a general rainfall back by the end of the period. Temperatures run below normal in the expected pattern.

DAYS 11-15 (MAY 28 – JUNE 1)

A low pressure dominated cool and unsettled pattern transitions to a drier and more progressive northwest flow pattern as we head through the final days of May toward the start of June.

DAYS 1-5 (MAY 17-21)

In a “wet” pattern dominated by low pressure, you have your nice times. Yesterday afternoon, for example, was one of those times. While the higher humidity you could feel in the air may have been a little uncomfortable for some, you can’t deny the feel of early summer was with us – sun and clouds, and no showers and thunderstorms to track (they stayed well west and north). Now we reach the weekend and a weather transition will take place as low pressure drifts eastward through the Northeast and southeastern Canada. A large surface low pressure circulation will pass to our north today and tonight, and then shift a bit east southeastward into the Gulf of Maine and the southern portion of Atlantic Canada through Sunday into Monday as well. During this time, upper level low pressure also drifts into and then across the region from west to east – in no really hurry during the trip. The weather outlook in general hasn’t changed since my last update. The aim of this update is to pinpoint the weekend shower threats in more detail. The windows-of-opportunity are somewhat limited, so we’re going to salvage the majority of hours at any given location rain-free versus wet on both days. Today’s best shower threat comes in a west-to-east sweep from late morning to mid afternoon, but any given location would rain for a relatively short period of time. Additionally, another passing shower or thunderstorm can take place from around sunset to late evening, again west to east, and again being of short duration where they would occur. The difference between today and Sunday will be the “feel” of the air. Today’s higher dew points in the warm sector will give the muggy feel, while tomorrow, cooler air and much lower dew points, along with a breeze, will add a bit of chill to the air. As we find ourselves in the northwesterly flow Sunday on the back side of low pressure, any sun that we see will simply help to ignite more clouds, and some of these clouds will produce showers. Our best shot at showers Sunday comes during the second half of the afternoon into the evening. Getting to Monday, the upper low’s impacts are still apparent, with more clouds wheeling around its back side, and still the threat of a few passing showers during the day, although it looks like the greatest threat comes early in the day – will refine that timing. High pressure provides fair weather Tuesday. Enjoy it, because another storm system is on the way, and the rain threat returns during Wednesday. I’ll get more into that threat on tomorrow’s update.

TODAY: Cloudy through midday with a passing shower possible west to east. Clouds break for sun after with a shower or thunderstorm possible mainly west of I-95 toward evening. Highs 62-69 South Coast, 69-76 elsewhere. Wind S up to 10 MPH becoming variable then SW 5-15 MPH late-day.

TONIGHT: Variably cloudy. A shower or thunderstorm possible until late evening. Fog patches in low elevations. Lows 55-62. Wind SW to W 5-15 MPH.

SUNDAY: Variably cloudy. Scattered showers, mainly late afternoon to early evening. Highs 62-69. Wind W to NW 10-20 MPH.

SUNDAY NIGHT: Partly cloudy. Lows 45-52. Wind NW 5-15 MPH.

MONDAY: Partly sunny. Isolated showers. Highs 61-68. Wind NW 10-20 MPH.

MONDAY NIGHT: Clearing. Lows 45-52. Wind NW 5-15 MPH.

TUESDAY: Sunny. Highs 62-69. Wind W 5-15 MPH.

TUESDAY NIGHT: Clear. Lows 45-52. Wind W under 10 MPH becoming variable.

WEDNESDAY: Clouding over. Rain arriving southwest to northeast. Highs 52-59. Wind E 5-15 MPH.

DAYS 6-10 (MAY 22-26)

Eyeing a coastal storm with wind/rain into May 22 along with well below normal temperatures. Improvement May 23. Memorial Day Weekend (May 24-26) early outlook: Upper level low pressure can produce diurnal scattered showers Saturday and Sunday before high pressure brings fair weather Monday. Obviously lower confidence that far in advance, but that’s an early call and will be updated and detailed as we get closer to it.

DAYS 11-15 (MAY 27-31)

Large scale pattern for the last 5 days of May starts out on the cool side followed by some moderation. We may have to watch yet another storm system just to the south early in the period, but unclear on how big a threat that would be for additional rainfall. Stay tuned…

DAYS 1-5 (MAY 16-20)

Weakening low pressure to our southwest drifts northward today into Saturday, merging with a more organized by maturing low pressure area moving eastward through the Great Lakes. The result here is a general southeast to south wind and humid conditions. Shower activity will be mostly nil during the day today as we have a lack of mid and high level moisture, and the lower clouds are thinning and breaking. In fact many areas away from the coast break out into a fair amount of sun at times. We’ll see a spring-typical temperature contrast from coast to inland too. Clouds become more dominant tonight and Saturday – though some breaks of sun are still possible Saturday. As the Great Lakes low, which will now have overtaken the weakening one, passes by to our north, a couple troughs and a cold front bring shower and thunderstorm opportunities to our region. The chance will be limited in the morning, better in the afternoon, and best in the evening. The low center, in response to the upper pattern, will then drift more to the east southeast across Maine and into the Atlantic to our northeast during Sunday, settling slowly and steadily to the east of our region by Monday, and finally away by Tuesday, when high pressure builds in. Sunday and early next week are less humid, cooler, and I’d love to say dry, but I cannot rule out additional scattered showers Sunday and isolated showers Monday as we’re still under the upper low’s influence.

TODAY: Areas of fog early. Clouds break for sun at times. Remote chance of a brief shower. Highs range from near 60 Cape Cod to near 80 interior valleys. Wind SE to S up to 10 MPH.

TONIGHT: Clouds dominate. Patchy fog. Chance of a shower. Lows 56-63. Wind S up to 10 MPH.

SATURDAY: Mostly cloudy. Showers and thunderstorms likely, favoring a couple hours between late morning and mid afternoon west to east. Highs 62-69 South Coast, 69-76 elsewhere. Wind S up to 10 MPH becoming variable then SW late-day.

SATURDAY NIGHT: Variably cloudy. Additional showers / thunderstorms likely. Patchy fog. Lows 55-62. Wind S 5-15 MPH shifting to W.

SUNDAY: Variably cloudy. Scattered showers, mainly in the afternoon and evening. Highs 62-69. Wind W to NW 10-20 MPH.

SUNDAY NIGHT: Partly cloudy. Lows 45-52. Wind NW 5-15 MPH.

MONDAY: Partly sunny. Isolated showers. Highs 61-68. Wind NW 10-20 MPH.

MONDAY NIGHT: Clearing. Lows 45-52. Wind NW 5-15 MPH.

TUESDAY: Sunny. Highs 62-69. Wind W 5-15 MPH.

DAYS 6-10 (MAY 21-25)

Hybrid blocking / progressive pattern. Watching the evolution of low pressure with a decent chance to bring wet weather in the May 21-23 time frame, but the exact details are currently uncertain. Improvement follows but upper level low pressure may keep it cool with at least some shower threat into the Memorial Day Weekend.

DAYS 11-15 (MAY 26-30)

Expected large scale pattern features a trough of low pressure in the eastern US with a couple wet weather chances and overall temperatures running below normal, but the pattern may relax toward the end of the period with a milder westerly flow.

DAYS 1-5 (MAY 15-19)

Slow pattern shift continues … broadening / weakening low pressure at upper levels and resultant surface low drifts northeastward and the southeasterly air flow we’re in now becomes more southerly Friday and Saturday. Another low pressure area moves eastward through the Great Lakes. This results in a modest warm-up and more humid spell of weather. We’ll have bouts of showers all 3 days, the most concentrated showers with embedded thunder coming through from south to north this morning, then a more scattered to isolated shower pattern much of the time – with lots of rain-free hours – until one more disturbance / cold front comes through from the west around the middle of the day Saturday with another batch of showers and storms. Once we get by that, low pressure shifts to our east but upper level low pressure still has to cross the region on Sunday. That day will be drier, a little cooler, but can still have a few passing showers around. Even on Monday, a fair, cool, dry day, we’ll see some clouds in the sky as a result of lingering cold air aloft with the upper level low pressure area just to our east.

TODAY: Cloudy. Widespread showers and embedded thunderstorms into mid morning then scattered to isolated showers thereafter. Any showers can contain downpours with some localized flooding issues. Patchy fog early. Highs 59-66 coast, 66-73 inland. Wind SE up to 10 MPH.

TONIGHT: Mostly cloudy. Chance of showers. Lows 53-60. Wind S up to 10 MPH.

FRIDAY: Mostly cloudy. Chance of showers. Highs 62-69 South Coast, 69-76 elsewhere. Wind S 5-15 MPH.

FRIDAY NIGHT: Mostly cloudy. Chance of a shower. Patchy fog, Lows 55-62. Wind S 5-15 MPH.

SATURDAY: Mostly cloudy. Showers and thunderstorms likely, favoring a couple hours between late morning and mid afternoon west to east. Highs 62-69 South Coast, 69-76 elsewhere. Wind S up to 10 MPH becoming variable then SW late-day.

SATURDAY NIGHT: Variably cloudy. Patchy fog. Lows 52-59. Wind SW to W 5-15 MPH.

SUNDAY: Partly sunny. Chance of a shower. Highs 62-69. Wind W to NW 10-20 MPH.

SUNDAY NIGHT: Partly cloudy. Lows 45-52. Wind NW 5-15 MPH.

MONDAY: Partly sunny. Highs 61-68. Wind NW 10-20 MPH.

DAYS 6-10 (MAY 20-24)

Hybid blocking / progressive pattern. The first couple days bring us fair weather with high pressure in control. This is followed by a period of unsettled weather with low pressure impacting the region – details TBD. Temperatures near to below normal.

DAYS 11-15 (MAY 25-29)

Expected large scale pattern features a trough of low pressure in the eastern US with a couple wet weather chances and overall temperatures running below normal.

DAYS 1-5 (MAY 14-18)

The process of migrating / breaking down of a Rex Block continues, with slow-motion weather changes the result. Low pressure to our southwest very slowly weakens, broadens, and drifts northeastward over the next several days. Yesterday, high clouds in the sky were battled by drier air and you saw that they had trouble thickening up. Mid level clouds were held off mostly to our southwest. By late-day, if you were sky watching you noticed an increase in clouds, but this morning you notice that hasn’t changed too much – with just some thicker high to mid level cloud cover across our southern areas while to the north the clouds are thin enough to allow some sun. This was my expectation when making yesterday’s forecast, leading to the wording that I used for today (Wednesday) of “limited sunshine / lots of clouds” while other forecasts you may have seen just called for “cloudy”. The latter is now becoming true for southern areas and eventually this will become the case for the region in general as the day goes on, but it’s still a slow process, with intervals of filtered sun still possible into midday at least across areas north of I-90. This may seem like a lot of explanation for one deck of clouds, but my aim is to give people an understanding of how this particular pattern is working on making our changes such a slow process. Anyway, once we get the clouds in, the atmosphere will moisten up enough to allow the chance of showers to increase as we get to this evening and tonight, and in pulses Thursday into Friday as we see our wind flow go from easterly to southerly. The surface humidity will be increasing, and you’ll feel that in the air quite noticeably by Friday, as well as Saturday. Those two days are when we’ll have an air flow out of the south. Saturday also continues the shower chance – although not a “washed-out” day, as there may only be a few hours total where any one area is impacted by rainfall. We do have to get a disturbance through here from west to east at some point Saturday when we can have a heaver bout of shower and thunderstorm activity. I’m still working on tweaking the expecting timing of that and won’t really be certain of it until Friday, but yesterday’s leaning was late-day / evening and today’s is just a little bit earlier (Saturday midday / afternoon). Stay tuned for more about that. Sunday, we’re into a drier western air flow, but upper level low pressure crossing the region can still allow a few showers to pop up with the aid of the sun’s heating, so I can’t leave that as a completely rain-free forecast either at this point.

TODAY: Filtered / limited sun favoring northern MA / southern NH morning, otherwise becoming mostly cloudy. A shower possible South Coast late-day. Highs 60-67 coast, 67-74 inland. Wind E up to 10 MPH.

TONIGHT: Mostly cloudy. Shower chance increases. Lows 52-59. Wind E to SE up to 10 MPH.

THURSDAY: Mostly cloudy. Showers most likely through mid morning, then a lower shower chance thereafter. Highs 59-66 coast, 66-73 inland. Wind SE up to 10 MPH.

THURSDAY NIGHT: Mostly cloudy. Chance of showers. Lows 53-60. Wind S up to 10 MPH.

FRIDAY: Mostly cloudy. Chance of showers. Highs 62-69 South Coast, 69-76 elsewhere. Wind S 5-15 MPH.

FRIDAY NIGHT: Mostly cloudy. Chance of a shower. Patchy fog, Lows 55-62. Wind S 5-15 MPH.

SATURDAY: Mostly cloudy. Showers likely, favoring midday & part of afternoon. Highs 62-69 South Coast, 69-76 elsewhere. Wind S up to 10 MPH becoming variable.

SATURDAY NIGHT: Variably cloudy. Chance of a shower. Lows 52-59. Wind SW to W 5-15 MPH.

SUNDAY: Partly sunny. Chance of a shower. Highs 62-69. Wind W to NW 10-20 MPH.

DAYS 6-10 (MAY 19-23)

This is the period of time where we’ll be in the much-mentioned hybrid block / progressive pattern. The upper pattern will attempt an omega (trough west central North America / ridge Great Lakes and eastern Canada / trough east of New England), with us on the fair weather eastern side of high pressure early next week – dry and seasonable / slightly cool weather. After this we see a progression of features as the pattern begins a transition to ridge western US / trough eastern US. This may cause some unsettled weather in our region by the middle to latter portion of next week, but I’m uncertain of details this far in advance.

DAYS 11-15 (MAY 24-28)

Strongest indications are for a trough of low pressure dominating the eastern US, including New England, including the WHW forecast area. This pattern would feature a couple opportunities for wet weather, but not an excessively wet pattern. Temperatures near to below normal. May 24-26 is the Memorial Day Weekend, where much scrutinizing of the weather expectations is done. I’ll be focusing on this period in detail as it nears.

DAYS 1-5 (MAY 13-17)

A slowly migrating Rex Block will result in slow weather changes heading through the balance of this week. As mentioned in the previous update, high pressure will try to hang on but drift to the northeast into Atlantic Canada. A surface high associated with the upper ridge has driven a weak back-door cold front into the region early today and this will result in a regional onshore (northeasterly) air flow, which will keep the coast cooler than inland areas. The same will generally be true for Wednesday and Thursday while we see the general air flow become easterly to southeasterly. This will be in response to the slow approach of a large but weakening low pressure circulation from the southwest – this being the low pressure portion of the aforementioned block. While the dry air wins the battle for a while, even allowing some sun Wednesday, eventually the moisture will increase enough to bring more dominant cloudiness and a shower chance Wednesday night and/or Thursday, and even more so as we get to Friday. By that time, a southerly air flow will have taken over, and it will become more humid as well. Any warm-up will be modest late week, and a southerly wind off the water south of New England means that it will be the South Coast’s turn to be ocean-cooled more directly on Friday. Saturday’s weather will be unsettled as we still have low pressure around while a disturbance from the west joins the party, increasing the shower chance. This does not look like a wet day from start to finish, but it’ll be a couple days before I can work out the timing of the best rain chances. Initially, I lean toward later over earlier, but don’t make any solid plans based on that idea at this point.

TODAY: Filtered sunshine through lots of high clouds. Highs 60-67 coast, 67-74 inland. Wind variable to NE up to 10 MPH.

TONIGHT: High clouds dominate. Lows 48-55. Wind NE to E up to 10 MPH.

WEDNESDAY: Limited sunshine / lots of clouds. Highs 60-67 coast, 67-74 inland. Wind E up to 10 MPH.

WEDNESDAY NIGHT: Mostly cloudy. Chance of a shower. Lows 52-59. Wind E to SE up to 10 MPH.

THURSDAY: Mostly cloudy. Chance of showers. Highs 59-66 coast, 66-73 inland. Wind SE up to 10 MPH.

THURSDAY NIGHT: Mostly cloudy. Chance of showers. Lows 53-60. Wind S up to 10 MPH.

FRIDAY: Mostly cloudy. Chance of showers. Highs 62-69 South Coast, 69-76 elsewhere. Wind S 5-15 MPH.

FRIDAY NIGHT: Mostly cloudy. Chance of a shower. Patchy fog, Lows 55-62. Wind S 5-15 MPH.

SATURDAY: Mostly cloudy. Showers likely, favoring the afternoon or evening. Highs 62-69 South Coast, 69-76 elsewhere. Wind S up to 10 MPH becoming variable.

DAYS 6-10 (MAY 18-22)

Low pressure shifts east of the area by the end of the weekend with cooler air and only a chance of a few passing showers May 18. High pressure builds in for fair weather May 19-20. Next round of unsettled weather follows for the middle of next week as low pressure returns.

DAYS 11-15 (MAY 23-27)

A cool northwesterly air flow is expected to dominate with mostly dry weather and one or two opportunities for passing showers. This time frame includes Memorial Day Weekend (May 24-26).

DAYS 1-5 (MAY 12-16)

A slow transition of the spring weather pattern continues over the next several days. Last week’s omega block (low West, high Plains, low East), as noted on yesterday’s blog post, transitioned to a rex block pattern (high North, low South). We’re currently under the influence of high pressure, but as we move through this week, the large scale features shift and the high slides to the east while the low to the south drifts northeastward, our way. However, there will be resistance from the high and the overall process will be quite slow to occur. This means that while we see an increase in clouds after today’s abundant sun, the clouds will struggle to thicken up into midweek, and any rain will be held at bay to our south and west as well. Finally by Thursday and Friday as we see the now broad and weaker upper low move further northeast, we’ll see a trend to a more southerly air flow and as a result more moisture with lots of clouds and increased shower chances. Neither of these days look like full on rainy “wash-out” kind of days though.

TODAY: Clouds scoot across southeastern NH / northeastern MA early on, otherwise abundant sunshine. Highs 60-67 Cape Cod / South Coast, 68-75 elsewhere. Wind W to SW 5-15 MPH.

TONIGHT: High clouds fan in from the southwest. Lows 48-55. Wind SW to variable under 10 MPH.

TUESDAY: Sun & high clouds. Highs 63-70 coast, 70-77 inland. Wind variable up to 10 MPH with coastal sea breezes.

TUESDAY NIGHT: High clouds increase. Lows 50-57. Wind SE up to 10 MPH.

WEDNESDAY: Limited sunshine / lots of clouds. Highs 60-67 coast, 67-74 inland. Wind SE up to 10 MPH.

WEDNESDAY NIGHT: Mostly cloudy. Lows 52-59. Wind SE up to 10 MPH.

THURSDAY: Mostly cloudy. Chance of showers. Highs 64-71, coolest coastal areas. Wind SE up to 10 MPH.

THURSDAY NIGHT: Mostly cloudy. Chance of showers. Lows 53-60. Wind S up to 10 MPH.

FRIDAY: Mostly cloudy. Chance of showers. Highs 63-70, coolest South Coast. Wind S 5-15 MPH.

DAYS 6-10 (MAY 17-21)

Continued slow pattern shift as upper level low pressure dominates but the core of which passes to our west then north. This starts us out in a southerly air flow which then trends more westerly. There are shower chances early in the period, the May 17-18 weekend, before a drying trend takes place. Temperatures near to slightly above normal for the period overall.

DAYS 11-15 (MAY 22-26)

Late month pattern features a broad trough of low pressure and mostly west to east flow, with a trend for more cool air from Canada – i.e., temperatures near to below normal, with mostly dry weather interrupted by brief shower chances. Memorial Day Weekend is May 24-26 as part of this expected pattern.

DAYS 1-5 (MAY 11-15)

The large scale pattern has now shifted from one block to another as part of the transition to the “hybrid” pattern I have referenced several times recently. Previously, the Omega pattern existed – cut off low western US, cut off low eastern US, ridge of high pressure between the two. Now, it’s a Rex Block – high pressure to the north, low pressure to the south, located over the central and eastern US. This pattern persists the next few days before itself starting a shift in response to more progression to it west and north. Eventually the features move. The eastern nose of the high pressure area will play a part in giving us fair weather from today through Tuesday, after which it will give way to a northeastward-drifting low pressure area that will increase our clouds and wet weather chances as we head through midweek. I don’t think it will be in a hurry to get all that wet here, though, as the low from the south will be broad and disorganized with no super organized areas of rainfall, instead a more broken rainfall pattern.

TODAY: Lots of sun / few clouds. Highs 65-72. Wind NW 5-15 MPH.

TONIGHT: Mostly clear. Lows 38-45 inland, coolest in valleys, 45-52 coast, mildest Boston. Wind NW under 10 MPH.

MONDAY: Mostly sunny. Highs 68-75. Wind W 5-15 MPH.

MONDAY NIGHT: Mostly clear. Lows 48-55. Wind WSW 5-15 MPH.

TUESDAY: Sun & high clouds. Highs 63-70 coast, 70-77 inland. Wind S to SE 5-15 MPH.

TUESDAY NIGHT: High clouds increase.. Lows 50-57. Wind SE up to 10 MPH.

WEDNESDAY: Limited sun / clouds dominant. Highs 60-67 coast, 67-74 inland. Wind SE up to 10 MPH.

WEDNESDAY NIGHT / THURSDAY: Mostly cloudy. Chance of showers. Lows 53-60. Highs 61-68. Wind SE to E up to 10 MPH.

DAYS 6-10 (MAY 16-20)

Pattern shift is slow, still in the hybrid block – low pressure not completely connected to the jet stream which becomes more progressive overall. The low pressure area that dominates the eastern US looks weaker than the one associated with the recent omega pattern. This pattern for us would deliver a southerly air flow shifting more westerly with time, but occasional shower chances with fair weather being dominant the majority of the time. Temperatures, while variable, would average near to slightly above normal.

DAYS 11-15 (MAY 21-25)

Heading into late month, the strongest indications are for a progressive pattern – general west to east flow – but with a mean trough in eastern Canada and the northeastern US, making us more susceptible to a shot or two of cool Canadian air with temperatures near to below normal. Overall pattern looks drier.